Method of converting granular or pulverulent material into lumps.



No. 792.449. PATENTED JU 1 I E. POHLI I NE 13, 905 METHOD OF CONVERTING GRANULAR OR PULVERULENT MATERIAL INTO.

LUMPS.

APPLICATION FILED 1130.10, 1904.

mzwdm' K yo WW,

UNITED STATES Patented June 13, 1905.

EDUARD POHL, OF HARSUM, GERMANY.

METHOD OF CONVERTING GRANULAR OR PULVERULENT MATERIALS INTO LUMPS.

SPECIFICATION forming part of Letters Patent No. 792,449, dated June 13, 1905.

Application filed December 10, 1904. Serial No. 236,324.

To all whom it may concern:

Be it known that I, EDUARD PoHL, engineer, of Harsum, in the German Empire, have invented certain new and useful Improvements in Methods of Converting Granular or Pulverulent Materials, such as Ores, Minerals, and Ashes, into Larger Lumps or Pieces, of which the following is a full, clear, and exact description.

My invention has for its object to treat granular or pulverulent materialssuch as ores, minerals, ashes, and the likein such a manner that larger lumps or pieces of regular or irregular shape or form are obtained.

I will now describe my process, reference being had, byway of example, to obtaining solid lumps or pieces from granular or pulverulent iron ores. The pulverulent ore is agglomerated by means of liquid slag or any other fusible material. The process is very peculiar and yields a product in which only a small quantity of the binding agent is contained. I obtain this result by dividing the molten material into numerous fine particles, which fall down as rain or spray on the granular ore and agglomerate the powder. The 'agglomerating material is used in a very small quantity, as it is divided into finest particles, whereby its surface is so much increased that it agglomerates larger quantities of granular ores. When carrying out the process, care must be taken that the granular ores to be agglomerated are intimately mixed with the molten slag reduced to spray. The means by which this mixing may be obtained are very various. Most suited is the well-known revolving retort which frequently is used in the manufacture of cement.

In the accompanying drawing a longitudinal section of an apparatus as used by me is given. It consists of a revolving retort a, open on both ends and lined inside with a suitable fireproof material. On its periphery there is fastened a toothed ring 6, with which gears a toothed wheel 0, rotated in any suitable manner. The retort a is arranged in an oblique manner, so that by its rotation the material charged at one end slowly advances toward the other. The higher end is closed by a charging device (Z, from which a tongue or guideway f extends into the inner end of the retort. At the other lower end a plate 9 is arranged, which only partly closes the same and leaves at the lower part an opening 0, from which the agglomerated material is discharged. In the plate there are arranged a spout g, nozzles it c', the spout 9 serving for conducting the molten slag into the retort, the nozzle II, for admitting compressed air, steam, or the like, and the nozzle 2' for injecting fuel, such as coal-dust. Underneath the discharge-openingothere may bearranged two rollers m m, which press the agglomerated ma terial in order to give it a stronger compressoin or coherence. With this revolving retort I carry out my process as follows: the granular or pulverulent material is charged into the rotort a at the high end opposite the spout g and nozzles it 1'', and by the rotation of the retort a it slowly advances toward the discharging end, being heated during that time to the required temperature by the injection of heated coal-dust and compressed air or steam. On the material thus heated is spread the liquid slag which passes through the flames of the coal-dust furnaces. The spray-like slag particles fall on the fine and heated ore and efiect the agglomeration of the different ore particles. In consequence of the rotation of the retort and of the falling slag-rain continuously new ore particles come in contact with the binding agent. In this manner lumps of a larger or smaller size are formed, which leave the retort through the opening 0. If it is required to give these lumps a higher compression or stronger coherence, they are caused to pass the two rollers m m or any other suitable device arranged underneath the discharge-opening. With the molten slag and the like large quantities of heat are introduced into the retort and transferred to the ore, so that very little coal is used for preheating purposes. If the agglomerated ore is to be charged into the blast-furnace, the shapeless lumps,especially after having passed the rollers, will be suited, as they are very strong and solid. They remain unbroken or uncrushed, even under the weight of the charge-column in the blast-furnace, until they reach the smelting zone and there get soft, together with the other charge. Sometimes it might be advisable to charge with the ore coke or small coal into the retort in order to give the finished product a certain porosity by which the reduction process in the blast-furnace is facilitated. If required, also, fluxes, such as chalk or limestone, may be added to the ores.

The finely-divided white-glowing liquid blast-furnace slag is an extremely cheap binding agent for my method, which, moreover, is available in large quantities; but my process is not limited to the use of blast-furnace slag. Many other substances may be used for the purpose of my invention, such as molten vulcanic ores, marl, phonolite, mixtures of slags and metals, or any other suitable molten material. If blast-furnace slag is not available, the necessary molten material is produced in a small shaft-furnace by smelting the required materials. Thomas slag may also be used with advantage. If it is intended to use my process for the production of ores rich in phosphorus, an addition of phosphorous substances, such as phosphates, is made to the ore or to the molten slag. I may also use with advantage molten metals, such as iron. The into fine spray like fused particles partly burn during their falling down, whereby the temperature of each particle is very considerably increased and the heating of the granular ore is materially assisted.

My invention may also very advantageously be carried out in combination with the roasting process. It is especially important for large-piece ores, such as spars, which fall to pieces when being roasted. The heat introduced by the slag is immediately transferred to the ore in consequence of the direct contact of the two materials, suddenly raises the temperature of the ore, and accelerates the roasting process. My invention is very efficient for the agglomeration of such ores which hitherto could not be totally roasted.

My invention may further be adapted for producing artificial stones or for burning town refuse and simultaneously forming slagstones. Of course suitable presses must be made use of in order to give the slag the required shape.

Having thus particularly described and ascertained my said invention and in what manner the same is to be performed, I declare what I claim is 1. A process for converting granular or pulverulent materials into pieces or lumps consists in mixing with said materials to be agglomerated finely-divided molten substances.

2. A process for converting granular or pulverulent materials into pieces or lumps, consists in preheating the said materials to be agglomerated and mixing therewith finely-divided molten binding agents.

3. A process for converting granularor pulverulent materials into pieces or lumps, consists in preheating the said materials to be ag glomerated and adding to the same binding agents and mixing with the mixture finelydivided molten slag substances.

4. A process for converting granular or pulverulent materials into pieces or lumps, consists in preheating the said materials to be agglomerated, adding to the same binding agents, then mixing with the mixture finelydivided molten slag substances and treating the pieces thus formed between rollers.

5. A process for converting granular or pul- Verulent materials into lumps, consists in roasting the materials and agglomerating the roasting agents, mixing therewith finely-divided molten substances and cohering the pieces thus formed.

6. A process for converting granular or pulverulent materials into pieces or lumps consists in roasting the said materials by introducing the materials to be agglomerated at one end of a revolving retort, injecting on the materials binding substances and molten materials in a finely-divided state and discharge the agglomerated materials at the other end cohering the pieces thus formed.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

EDUARD POI-IL. Witnesses:

LEONORE RAsoH, H. HALL HALL. 

